Blueberries in secondary- headspace?

[autonomist3k]

I'm making a blueberry wheat and I'm going to rack on top of some blueberries, I'm wondering how much headspace I need?
it's a 2.25 gallon batch in a 3 gallon carboy, once I add the blueberries I don't think there will be any headspace. should I secondary it in my 5 gallon fermenter to allow for fermentation of the blueberries? or do they not ferment that much to worry about it?

 

[Wolfbrau]

Blueberries have serious bugs on their exterior. They can cause lacto infections all day long, and they will ferment. Consider juicing them and using a vodka tincture.

If you're bottle conditioning, you have to adjust the recipe for the dryness you'll get from them fermenting. A good way to do that would be to use lactose powder. If you're kegging it, hit it with sorbate, wait a few days, then add the blueberry juice. Then you can force carbonate.

 

[autonomist3k]

Thanks, I already did it though.
I took frozen berries, vacuum sealed them and refrozen them, when I was ready I kept them in the bag and heated them up to 170 for a while to pasteurize them, then cooled them to 70 and dumped in the fermenter.

 

[autonomist3k]

As for adjusting for dryness, I never thought of that, I'll try it next time.

 

[Wolfbrau]

It's cool, mang. RDWHAHB. Sorry I couldn't help sooner. As far as I know, this beer will win an NHC gold as-is!

 

[autonomist3k]

It's a vanilla blueberry wheat, I hope it turns out amazing!